From my experience, it is the method of adding strong acid to an aqueous solution that is actually the cause of high corrosion. In the chemistry lab we added strong acid to water, never water to strong acid. Partial reason was that the large volume of water absorbed the heat of dilution...
lizking
Thanks for correcting my error. The 116% MAWP is the max overpressure for multiple RV's.
JLSeagull
Most distillation columns run at a fixed pressure. (Floating pressure control is unusual.) Providing an elevated (above normal) pressure control setpoint and activating a depressuring...
Without viewing a P&ID, relief valves are required to protect the distillation column as a pressure vessel. Multiple relif valves (likely staged) would allow full flow at 116% (two valves) or at 121% (three or more valves) overpressure.
Relief valves are set at or below column design...
schnipp
A clarification on setting the rate is due. You can set the inlet flowrate and adjust it for cycles of concentration (based on lab results) periodically. Excess water will overflow as CT blowdown needed to maintain cycles of concentration.
As an alternate (method #2), you can set and...
Check the following link for a graph of "pH of Caustic Soda at Various Concentrations (wt%)". The graph has limited range. It can be extrapolated on semi-log paper.
http://www.dow.com/webapps/lit/litorder.asp?filepath=causticsoda/pdfs/noreg/102-00484.pdf&pdf=true
Main link is...
For the most part, mechanical level systems are subject to wear and require continual monitoring.
On one application that was handling 15% to 20% solids, I had success with a bubbler type level transmitter and a pneumatic control loop. Original mechanical gizmo with a float and a chain...
Valid observation schnipp if you are expecting a closed-loop control on the water level in the CT basin.
In reality, that level does not need to be controled by a level controller. Setting make-up rate to a fixed flowrate and allowing the (oil) skimmer blades for blow-down achieves the same...
Thanks to 25362 for a more precise definition of pH. Let me expand the concepts further.
pH is a measuurement of H+ ion concentration.
In aqueous solutions, pure water has a neutral pH of 7.0. That is equivalent to having a presence of 10exp(14-7.0) H+ ions and 10exp(14-7.0) OH- ions...
The reduced CO2 rate is based on Hydrogen content of an alkane being converted to H2. (CnH2n+2 + H2O to H2 + CO2 + CO) There is excess steam fed into the process to prevent coking.
With a fixed Hydrogen production, Butane is more efficient in producing H2 than Naphtha. (Butane is C4H10 and...
Trying to locate a reliable BTEX Analyzer / Monitor for a Petrochem water effluent stream. Range of 0 to 20 PPM is desirable.
The instrument will be located outdoors and requires NRTL Approval (ie UL, FM, or cCSAus) for Class 1 Div 2 Group C,D.
Any experience out there?
In response to JStephen’s comment “In fact, it is not uncommon to have overflow slots or nozzles on petroleum tanks”, I believe that the observation may be actually refer to vents that are present in an IFR tank just below the roofline. These vents prevent pressure or vacuum load on the...
If the process uses SMR as the front end, several areas need to be considered.
A. The two feeds have a different steam to carbon ratio and method of vaporization. Calculate the expected yields.
B. The by-product CO2 will be produced at a slightly reduced rate.
C. Depending on CO2 removal...
It concerns me that someone is considering an overflow system for a situation that should be avoided in the first place.
From the practical point, any nozzle on a side of a tank would interfere with external floating roof seals. As the liquid reaches the nozzle elevation, the seal would be...
From my experience, a control valve followed by a restriction orifice worked well in preventing cavitation and associated damage.
Design process uses the nominal flowrate to size the back-pressure orifice. In a case of 1600 psig dropping to 100 psig, allow the orifice plate 400 psig inlet...
